Purpose:This paper describes the strategies and practices of National Science Library(NSL),Chinese Academy of Sciences(CAS)in promoting open access(OA)and developing OA resources.Design/methodology/approach:Multi-facet frameworks are devised to guide the development of OA strategies and practices.Key OA initiatives are briefly described along the main aspects of the strategies as they contribute to implementation of the OA strategies.Findings:NSL defined its role as the Chief OA Officer for CAS and a key OA promoter for China.Accordingly,NSL has engaged in multiple fronts of promoting OA,including development of OA strategies for CAS,establishment of itself as an OA knowledge&promotion center,development of the CAS IR system,and support for OA publishing by CAS authors.Research limitations:OA is still evolving,so are the strategies and practices as many actions are experimental and explorative in nature.Open books,open data,and open educational resources are yet to be covered.Comparative studies are needed,so is the evidence-based impact analysis.Practical implications:Institutions can adopt,adapt,or compare with examples and lessons learned are described here.Originality/value:The multi-faceted frameworks,working principles,and lessons learned are based on NSL’s practices which can be valuable to the overall OA development. Purpose: This paper describes the strategies and practices of National Science Library (NSL), Chinese Academy of Sciences (CAS) in promoting open access (OA) and developing OA resources. Design / methodology / behavior: Multi-facet frameworks are devised to guide the development of OA strategies and practices. Key OA initiatives are described along the main aspects of the strategy as they contribute to implementation of the OA strategies. Findings: NSL defined its role as the Chief OA Officer for CAS and a key OA promoter for China.Accordingly, NSL has engaged in multiple fronts of promoting OA, including development of OA strategies for CAS, establishment of itself as an OA knowledge & promotion center, development of the CAS IR system, and support for OA publishing by CAS authors. Research limitations: OA is still evolving, so are the strategies and practices as many actions are experimental and explorative in nature. Open books, open data, and open educational resources are yet to be covered. Comparati ve studies are needed, so is the evidence-based impact analysis. Practical implications: Institutions can adopt, adapt, or compare with examples and lessons learned are described here. Originality / value: The multi-faceted frameworks, working principles, and lessons learned are based on NSL’s practices which can be valuable to the overall OA development.